In the context of which one of the following are the terms 'pyrolysis and plasma gasification' mentioned?

Defines pyrolysis as thermal decomposition of organic matter in absence of air and describes the syngas/char/liquid products produced by heat-driven breakdown.

A student could extend this by checking whether similar thermal decomposition is used to break down mineral-bearing matrices or electronic waste to liberate rare earths.

States pyrolysis and gasification are emerging technologies used to process waste and generate useful products (waste-to-energy).

One could reasonably investigate whether these waste-processing routes are applied to wastes that contain rare earths (e.g., electronic waste, monazite processing residues).

Explains gasification/pyrolysis as chemical processes that convert complex feedstocks (biomass) into useful products, showing these are general-purpose high-temperature conversion methods.

Use this pattern to ask if the same high-temperature conversion concepts are adapted to mineral or ore processing for REE recovery.

Defines plasma as an ionised, high-energy state of matter (ionised gas), implying plasma-based processes can provide high temperatures/energies.

With basic knowledge that high temperatures can break down or melt materials, a student could test whether plasma gasification is used to treat mineral sands/residues to separate or free rare earth elements.

Notes thorium is a by-product of extracting rare earths from monazite sands, identifying a specific mineral source and associated by-products.

Combine this mineral-source fact with thermal/thermal-plasma processing clues to explore whether pyrolysis/plasma gasification are applied to monazite sands or their residues to recover REEs or separate thorium.